Detection of equine antiplatelet and antineutrophil antibodies by enzyme-linked immunosorbent assay.

This research study focuses on the standardization and application of an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against platelets and neutrophils in horses. The antibodies were raised in rabbits and a heterologous system, including horse platelets or neutrophils, was employed. The research revealed that this ELISA technique was highly sensitive and capable of detecting these antibodies to a very high titre. Furthermore, the test showed utility even four to five weeks after storage at specific temperatures.

Assay Standardization and Application

• The team standardized an enzyme-linked immunosorbent assay (ELISA) with the goal of detecting antibodies against platelets and neutrophils in horses. These antibodies were raised in rabbits.
• A heterologous system comprising horse platelets or neutrophils was put into use. Some of the main components of the standardized procedure included an Immulon type 3 plate, a 1 per cent gelatine blocking solution, and a poly-L-lysine buffer as a coating solution.
• Other essential components included 90 microliters of test serum, an antibody conjugated with horseradish peroxidase, and o-phenylenediamine dihydrochloride serving as a substrate. Unfixed antigen was also used in the procedure.

Optatinum Detection of Antibodies

• The scientists found that 250,000 unfixed platelets or neutrophils were needed per well for the optimal detection of antibodies.
• Furthermore, unfixed cellular antigens performed as well as their extracts and were more effective than antigens fixed with paraformaldehyde for antibody detection.

Storage and Sensitivity Conditions

• It was established that microtitre plates coated with platelet or neutrophil antigens could be stored at 4 degrees and -70 degrees Celsius for up to four to five weeks without a considerable reduction in antigenicity.
• The ELISA procedure proved to be highly sensitive and could detect antiplatelet antibodies with a titre up to 1:204,800 and antineutrophil antibodies to a titre of 1:51,200.

Cross-reactivity and Detection of Antibodies

• While some degree of cross-reactivity was observed between antiplatelet and antineutrophil sera for neutrophil and platelet antigens, it was minimal and reported at only a 1:1600 ratio.
• It was also found that platelet-associated antibodies could be detected in samples where platelets had been pretreated with 1:2 and 1:8 dilutions of antiplatelet serum.
• In an isologous equine blood typing serum sample of 100, nine samples tested positive for antiplatelet antibodies and three tested positive for antineutrophil antibodies using the standardized ELISA technique.